Asymmetrical indigoid dyestuffs



United States Patent ASYMMETRICAL INDlGOlD DYESTUFFS Jakob Mueller,Mueuchenstein, Switzerland, assignur to Ciba Limited, Basel,Switzerland, a Swiss firm No Drawing. Application August 18, 1952,

Serial No. 305,085 Claims priority, application Switzerland August 23,1951 9 Claims. (Cl. 260-332) This invention provides new asymmetricalindigoid vat dyestuffs which are derived from aS-alkoxy-tS-halogen-3-oxythionaphthene, more especially theoxythionaphthene of the formula or from a derivativeof such anoxythionaphthene'reactive in the 2-position.

These new dyestufis are made in accordance with the invention bycondensing a 5-alkoxy 6:halogen 3eoxythienaphthene or a derivativethereof reactive in the 2-position with a component suitable for theproduction: of indigoid "vat dyestuffs.

The said 5-alkoxy-6-halogen-3-oxythionaphthcnes preterably contain analkoxy group of the lowerrseries, especially an alkox-y group containingup to 4 carbon atoms, such as a butylox-y-, or propyloxygroup or withadvantage an ethoxyor methoxy-group.

The 5-alkoxy-6-halogen-3-oxythionaphthenes used. as

starting materials can be made by. methods in themselves known, forexample, by the xanthate method from 4-alkoxy-Ta-halogen-l-aminobenzenes, for-example, :from .4- ethoxyor4-methoxy-3-bromo-l-aminobenzene or 4- ethoxy-3 -chloro-l-aminobenzene,and especially 4-r-nethoxy-S-chloro-l-aminobenzene, by .way of thetcortesponding thioglycollic acids. The ring closure .of thethioglycollic acids to form the oxythionaphthenes can be brought aboutwith the aid of phosphorus trichloride to form the acid chloridefollowed bytreatment with aluminium chloride, advantageously at a lowtemperature of about to 5 C. (in order to avoid splitting off an alkoxygroup).v However, ,rriug tclosure may, also the brought about in thedesired mannerby the use .ofzchlorosulfonic acid ,as condensing agent,especially if the temperature is below .0 C. so as .to void to -aconsiderable extent the formation of the corresponding. symmetrical]dyestufl.

. As components ,suitablewfor the production ;o f.indigo id dyestulis,which components muss-of course, ;be-tdifier.e lt from the.oX-ythionaphthenes used in :erderto tobtainzasyms metrical dyestuffs,there ,come into consideratiqn, for example, other oxythionaphthenes ortheir reactive derivatives, such as their anils, especially thedimethylaminoanils. As examples there maybe mentioned 6-chloro-3-oxythionaphth'ene, '4:S benZo-3-oxythionaphthene,benzo-7-chloro-3-oxythionaphthene, t-methyl-6-chloro-3-oxythionaphthene,6-methoxyor 6-ethoxy 3-oxythionaph thene,5-methyl-6-chloro-3-orry4thionaphthene and 4 :'7d imethyl-5-chloro3-oxythionaphthene. Isatins and the isatin chlorides obtainabletherefrom in known manner can also be used for the condensation, forexample, 5 :7-.dibrom-;isatin-and 4methyl-iehloroJ-methxy-isatin andespecially their-chlorides.

Thecondensationmaybe-carriedout intknown manner by bringing thecomponents together in aneinert solvent,

2,735,853 Patented Feb. 21, 1955 such as benzene or a chlorinatedbenzene, especially monochlorobenzene, for example, at a slightly raisedtemperature. In choosing the components it is necessary, as is known totake care that they are in diiferent states of oxidation, forexamp'le,one of the components may be in the form of the oxythionaphthene and theother in the form of the anil, isatin or isati-n chloride.

The dyestuffs so obtained can be used in known manner for dyeing a verywide variety of materials such as wool, silk, superpolyamide fibers,cellulose acetate silk, and especially fibers of vegetable charactersuch as cotton, linen and staple fibers of regenerated cellulose.However, they are especially suitable for printing by the usual methods,for example, by the so-called potash printing process. The .dyestuifsyield tints of predominantly covered shades, which are distinguished bygood properties of fastness, especially by good fastness to light.

The dyestufls can be converted in known manner into leucosesterderivatives, especially sulfuric acid leucoesters and can be used indyeing and printing by the methods usual for this class of dyestuifs.

The following examples illustrate the invention, the parts andpercentages being by weight:

Example 1 28.5 parts of 5-methoxy-6-chloro-3-oxy-thionaphthene aredissolved in 1000 parts of chlorobenzene and condensed with 43.6 partsof the 2(para-dirnethylarnino)- anil of 4:5-benz0 3-oxy-thionaphthenefor a few hours at 8090 C. The precipitated dyestuff, which is obtainedin good yield is filtered off, washed with chlorcbenzene and alcohol anddried. The dyestufi is of the formula andis a brown-violet powder givinga blue-violet coloration in concentrated'sulfuric acid. The dyestufi'yields by the :usual potashprinting process dark Ibrown tints of verygood .fastness to light.

The same dyestufi isobtainedby condensing 4:5-benzo- 3-.oxythionaphthcnewith the Z-(para-dimethylamino} anil -of 5-methoxys6-chloro-3-oxythionaphthene.

Example 2 40.8 parts of the 2-(para dimethylamino)-anil of 6-chloro-3-oxythionaphthene are introduced into a solution of 27.7 'parts'of 5-met-hoxy-6-chlo'ro-3-oxy-thionaphthene in 1000 parts ofchlorobenzene, and the condensation is carried on for a-fewhoursat 90 C.The resulting dyestuff of the formula me -obtained .on cotton by theusual printing processes violet-red ttintsaofv excellent tastness tolight.

Example 3 31 parts of 5-methoxyr6 chioro-3 oxythionaphthene aredissolved in .l40.0:-par t s of :chlorobenzene, 52.9 parts of hZttnaradimethrhmino)z nilof 5:6-benzo-7-ch1oro- 3-oxythionaphthene, andthe condensation is carried on for a few hours at 80-90 C. The resultingdyestufi of the formula /O\()\ C O HaC-O tints of very good fastness tolight.

In an analogous manner the dyestufis given in the following table areobtained from 5-methoxy-6-chloro-3- oxythionaphthene Coloration Cglor gt:ihe in totrlieenlgzf g yes u re e an (uric acid Condensed with the2-(paradimethylamlno)-anll of:

4 methyl 6 chloro oxblue-red green bordeaux.

ythlonaphthene. 6 mothoxy 3 oxythlobordeauxflu violet red-brown.

naphthene. G-ethoxy-3-oxythtoviolet red... .-d bordeaux.

naphthene. 5 methyl 6 chloro 8 red-violet... green red-violet.

oxythlonaphthene. 4:7 dlmethyl 5 chlorodo do D0.

3-oxythlonaphthene.

C H; violet .Q. violet-red. grey.

condensed with 4-methyl-5- blue-violet. green blue.

ehloro 7 methoxy lsattn chloride.

Example 4 56 parts of 5:7-dibromisatin are converted by heating with 45parts of phosphorus pentachloride in 800 parts of chlorobenzene intoisatin chloride. Into the solution are stirred 38 parts of5-methoxy-6-chloro-3-oxythionaphthene dissolved in 1300 parts ofchlorobenzene. The dyestuff, which is immediately precipitated, isfiltered off after about 1 hour and worked up in the usual manner. Thereis obtained a violet powder which gives a blue-green coloration inconcentrated sulfuric acid. The dyestuff yields on cotton by the usualprinting processes dark blue tints of good fastness to light.

Example 5 22.8 parts of 5-ethoxy-6-chloro-3-oxythionaphthene arecondensed with 33.2 parts of the 2-(para-dirnethylamino)- anil of4:S-benzO-3-0Xythi0naphthene in 800 parts of chlorobenzene for a fewhours at 80 C. The resulting dyestuffs of the formula o o co CHtO \C C/is obtained. It is a brownred powder which yields redbrown tints oncotton when applied by printing processes.

In the same manner there is obtained from 27.3 parts of5-ethoxy-6-bromo-3-oxythionaphthene and 33.2 parts of theZ-(para-dimethylarnino)-anil of 4:5-benzo-3-oxythionaphthene in 900parts of chlorobenzene by the usual method of condensation, the dyestuflof the formula CzHgO in the form of a brown powder, which yields browntints on cotton by the usual printing processes, which tints are of asomewhat more yellowish shade than those obtained with the dyestuff ofExample 1.

The 5-alkoxy-6-halogen-3-oxythionaphthenes used in the foregoingexamples can be prepared as follows:

77.6 parts of 3-chloro-4-methoxy-l-aminobenzene hydrochloride arediazotized in 800 parts of water, 200 parts of ice and 60 parts ofhydrochloric acid with a solution of 28 parts of sodium nitrite in partsof water. The diazo solution so obtained is run at about 70 C., whilestirring, into 80 parts of potassium xanthate, 400 parts of water andparts of sodium carbonate. The xanthate ester which separates isisolated and hydrolyzed at 80 C. with 300 parts of alcohol and 100 partsof caustic soda solution of 40 B. After the addition of an alkalinesolution of 40 parts of chloracetic acid in 600 parts of water, thecondensation is brought about and the alcohol is simultaneouslydistilled off. When the condensation is finished, the mixture isdissolved with water, filtered to remove impurities, and thethioglycollic acid is precipitated from the filtrate by means of mineralacid. The resulting 3-ch1oro-4-methoxybenzene-l-thioglycollic acid ofthe formula crystallizes from acetic acid in lamellae having the lustreof mother of pearl and melting at 1l51l6 C.

By using instead of 77.6 parts of 3-chloro-4-methoxy-l aminobenzenehydrochloride, 83.2 parts of 3-chloro-4- ethoxy-l-aminobenzenehydrochloride or 95.4 parts of 3-bromo-4-methoxy-l-aminobenzenehydrochloride, and diazotizing in 1000 parts of water (instead of 800parts), there is obtained in the same manner 3-chloro-4-ethoxy-'l-thioglycollic acid of the formula C|H5O S-CH1*COOH which crystallizesfrom dilute alcohol in the form of colorless needles melting at 103 C.or 3-bromo-4- methoxy-l-thioglycollic acid of the formula CHa-OS-CHr-COOH which crystallizes from chloroform in the form of densecrystals melting at ll0-1-1l C.

on -oO-s-oHr-oooH which crystalliz es from-dilute alcohol in the form oflustrous lamellae melting at 474 8 C.

The aforesaid thioglycollic acids can be converted into thecorresponding oxythionaphthenes, for example, as follows:

20 parts of 3-chloro-4-methoxybenzene-l-thioglycollic acid, 30 parts ofchlorobenzene and 9 parts of phosphorustrichloride are heatedforone houron a boiling water bath under a reflux condenser. The resulting solutionof the acid chloride is decanted from v a small amount of phosphorussludge, and rthen run at -5 C., while stirring into 15 parts ofanhydrous aluminum chloride and 70 parts of chlorobenzene. The reactionmixture is thenstirred for a few hours at that temperature. The.orange,..colore dreaction mass is :stirred into 100 parts of ice and 5parts of hydrochloric acid and then the chlorobenzene is distilled offwith steam. After cooling the crude oxythionaphthene is filtered 01f,dis solved by boilingin dilute caustic soda solution, filtered toremove, a small amountofa resinous residue, and the filtrate isprecipitated-with mineral'acid, wherebyS-methoxy-6-chloro-S-Oxythionaphthene of the formula \OHa I isprecipitated in a white fiocculentform. From dilute acetic acid thereareobtainedncolonless needles melting at 195 C.

-300-partS-of chloresulfonic acid are cooled to --7 =C., and -40 partsof 3-chloro-4-methoxy-l-thioglycollic acid are slowlyintroducedrwhilestirring, When the addition iscornplete, the mixture isstirred for a few hours at that temperature. The darkgredebrownsolution.is introduced into ice water, whereby5-methoxy-6-chloro-3-oxythionaphthene is precipitated in a reddish whitefiocculent form. By dissolving it in dilute caustic soda solution,filtering it ofi and precipitating with mineral acid, the product can befreed from traces of the symmetrical dyestuif.

50 parts of 3-chloro-4-ethoxybenzene-l-thioglycollic acid are heatedwith 21 parts of phosphorus trichloride in 75 parts ofortho-dichlorobenzene for one hour under reflux on a boiling water bath.The resulting solution of the acid chloride is decanted to separate itfrom a small amount of phosphorus sludge, and the solution is run at 0-5C. into 38 parts of aluminum chloride in 180 parts ofortho-dichlorobenzene. The whole is stirred for a few hours at 0-5 C.The orange colored reaction mass is introduced into 250 parts of ice andparts of hydrochloric acid, and the ortho-dichlorobenzene is distilledoff with steam. After cooling, the precipitated oxythionaphthene isfiltered oil, and, for the purpose of purification, is dissolved indilute caustic soda solution by boiling, filtered, and the filtrate isacidified with hydrochloric acid. In this manner5-ethoxy-6-chloro-3-oxythionaphthene of the formula is precipitated in awhite fiocculent form. By. recrystallization from acetic acid it yieldsfine colorless needles melting at 139 C.

By using, instead of. 3-chloro-4-ethoxybenzene-l-thioglycallic .acid,the .same amount of 3-.bromo-4-methoxybenzene-.1 -.thiog1y cQ1lic acidor 3-bromo-4-ethoxybenzenel-thijoglycollic marina- 19 .or 18 parts ofphosphorus trichloride, respectively, (instead of 21 parts), there isobtained 5-methoxy-61bromo 3-oxythionaphthene of the formula whichcrystallizes from glacial acetic acid in the form of broad lustrousneedles melting at 2l32l4 C., or 5ethoxy-6-bromo-'3-oxythionaphthene ofthe formula Example 6 parts ,of thedyestuff obtained as described inExample 1 are well moistened with 20 parts of alcohol and 120 parts ofwater, then mixed with 700 parts of potash thickening, 30- parts.;iof acaustic soda solution of 36 B.

and ZQ parts of "hydrosulfite concentrated powder, and heated to 501to60 C. After cooling, 80 parts of sodium formaldehyde -sul foxylate areadded and ground in a Wet color mill. After printing and drying thematerial, it is steamed for-8aminutes in a Mather-Flatt apparatus freefrom air, rinsed in cold water, then re-oxidized at 40 C., rinsed with'3 parts per liter of perborate and 2 parts of acetic acid of 40 percent strength, and soaped for 10 minutes at -90 C. Finally the materialis again rinsed well. I

The potash'thickening is prepared as follows:

1000 parts=1 kilogram.

What is claimed is: 1. An asymmetrical indigoid vat dyestufi of thegeneral formula wherein X stands for a member of the group consisting ofNH- and S-, wherein the alky radical contains at the most four carbonatoms, and wherein R stands for an aromatic radical containing at themost two rings both of which are six-membered carbon rings, and Y isselected from the group consisting of hydrogen, halogen, alkoxy andalkyl with at the most four carbon atoms.

2. An asymmetrical indigoid vat dyestuif of the general formula whereinthe alkyl" radical contains at the most four carbon atoms, and wherein Rstands for an aromatic radical containing at the most two rings both ofwhich are six-membered carbon rings, and Y is selected from the groupconsisting of hydrogen, halogen, alkoxy and alkyl with at the most fourcarbon atoms.

' 3. An asymmetrical indigoid vat dyestuff of the general formulawherein the alkyl radical contains at the most four carbon atoms andwherein R stands for a benzene radical, and Y is selected from the groupconsisting of hydrogen, halogen, alkoxy and alkyl with at the most fourcarbon atoms.

5. The thioindigoid vat dyestuff of the formula CO CO 6. Thethioindigoid vat dyestutf of the formula 00 0o 6Ca-0 7. The thioindigoidvat dyestuff of the formula /C0 C0 \C=C/ 8. The thioindigoid vatdyestutf of the formula 9. The thioindigoid vat dyestuff of the formulaReferences Cited in the file of this patent UNITED STATES PATENTS HaC-OOTHER REFERENCES Guha: Chem. Abstr. 33:7779 (1939); 3911539 (1945);39:4489 (1945); 40:5253 (1946).

1. AN ASYMMETRICAL INDIGOID VAT DYESTUFF OF THE GENERAL FORMULA